Engine fuel control system and apparatus for use therein



United States Patent [72] Inventors Donald F. Drapeau l-lolyoke, Massachusetts; Normand P. Holcomb, Warehouse Point, Connecticut [21] Appl. No. 776,671 [22] Filed Nov. 18, 1968 [45] Patented Oct. 27, 1970 [73] Assignee AMBAC Industries, Incorporated Garden City, New York a corporation of New York [54] ENGINE FUEL CONTROL SYSTEM AND APPARATUS FOR USE TIIEREIN 3 Claims, 4 Drawing Figs.

[52] U.S. Cl 123/179, 74/110, 254/31 [51] Int. Cl ..F02n 11/08, F02n 1 1/10 [50] Field ofSearch 123/179(G1 179(B).140.3,140(Cur):74/110(Cur):254/31 [56] References Cited UNITED STATES PATENTS 2,269,704 1 1942 Berry 123/179 2,940,437 6/1960 Groezinger 123/179 Primary ExaminerMark M. Newman Assistant Examiner-Ronald B. Cox Attorney-Howson & l-lowson ABSTRACT: In a diesel fuel engine system which requires Preferably the electromagnetic clutch comprises a pair of coaxial reciprocable plungers spring-biased toward one end of the clutch and against each other, together with an electrical winding which produces a magnetic field holding the two plungers together only when the starter is operating. To start the engine, the operator operates the usual starter switch button and the manual excess fuel control, whereby the fuel control member is moved to its excess fuel position; when the starter button is released, the reciprocable clutch plungers become free of each other, the excess fuel control member is spring returned to its normal engine-running position, and the manual fuel control knob becomes ineffective to move the excess fuel control member until the starter is again operated. Preferably the manual control and the clutch plunger connected thereto are also spring-returned to their normal englue-running positions.

BATTERY O GOVERNOR FUEL APPARATUS INJECTION PUMP ENGINE FIG. I.

-O BATTERY w 8 mww M, mfim 5 0O V mm a 4 v a FM VP N @m w 4 mm .4 m P 2|. E U M DN mu w 7. m x n Y i a f E a 2 m 9 6 J N E \m al A E TT 4 mm z 9 Patented Oct..27, 1970 ENGINE FUEL CONTROL SYSTEM AND APPARATUS FOR USE THEREIN BACKGROUND OF THE INVENTION There are a number of types of engines in which it is important to be able to operate a fuel control member to a particular position during starting of the engine, and to discontinue and prevent such operation after starting of the engine. While the fuel control member may, for example, correspond to a choke control in a gasoline engine, the present invention will be described in detail with particular reference to operation of the excess fuel control member of a diesel engine to provide excess liquid fuel only during engine starting. Typically such a system will include the diesel engine itself, a fuel injection pump for injecting fuel into the engine cylinders, governor apparatus for controlling the fuel injection pump so as to control engine speed, and an electric starter connected in series with a storage battery and with a starter switch for cranking the engine when the starter switch is operated. The governor apparatus may comprise any of a number of different types of controls, but is typically provided with a fuel control member having a normal or reference position for normal running of the engine and having a start position to which if it can be actuated to introduce excess fuel into the engine cylinders as desired for starting purposes.

While a manual control can be connected directly to the excess fuel control member to operate it during starting, with such an arrangement there is then no assurance that the excess fuel condition will not continue or be reinitiated after the starting operation is ended. Various arrangements have been proposed for limiting the excess fuel condition to the starting time, but they typically have one or more drawbacks such as complexity of construction, expense, difficulty of insertion into a preexisting system, lack of reliability in preventing excess fuel operation at times other than starting, excessive current drain, and others.

Accordingly, it is an object of the present invention to provide a new and useful system for operating a fuel control member during starting of an engine.

Another object is to provide such a system which provides easy and reliable operation of the fuel control member during the starting operation and prevents such operation after starting of the engine.

A further object is to provide such a system which utilizes electric current during engine starting to enable operation of a manual fuel control, and in which the amount of electric current required is relatively small.

It is also an object of the invention to provide apparatus for accomplshing the above-described operation which is readily insertable into preexisting engine systems.

SUMMARY OF THE INVENTION In accordance with the invention, these and other objects are achieved by the provision of a system comprising an engine, engine fuel control means having a start position suitable for use during starting of the engine and having another position suitable for use after the engine has been started, and a starter for the engine, in which system there is employed a normally-disabled control manually-operable, when enabled, to move the fuel control means to its start position but inoperable, when disabled, so to move the fuel control means, and means responsive to operation of the starter to enable the normally-disabled manually-operable control so long as said starter is operating. Preferably the means responsive to operation of the starter comprise electrically-energizable coupling means including a first force-transmitting member connected to said fuel control means, a second force-transmitting member connected to said manually-operable control, spring means biasing said second force-transmitting member, and an energizing winding responsive to application of voltage to said starter for exerting a magnetic efiect to bond said first forcetransmitting member to said second force-transmitting member while said starter is operating.

In operation, when the starter is being operated the coupling means serves to bond the first and second forcetransmissive members to each other so that when the manually-operable control is operated the fuel control means is thereby moved to its desired start position. However, as soon as the starter is deactuated (which normally occurs as soon as the engine has started), the coupling means is deenergized, the first force-transmsissive memberis released from the second force-transmissive member to permit return of the fuel control means to its normal position, and the manuallyoperable fuel control is thereafter ineffective to operate the fuel control means until the next starting operation. Preferably the fuel control means is spring-biased toward its normal, or engine running, position so that upon release it returns to this normal position, and preferably the manually-operable fuel control is also spring-biased toward its reference position so as to return thereto when released, in readiness for a subsequent starting operation. The apparatus automatically returns the fuel control means to its normal position when the engine has started, and prevents operation thereof during normal engine running. In addition, the coupling means is energizable to produce the desired coupling of the force-transmissive members in response to relatively small currents, since the energizing winding is not required to move a solenoid arm, but merely serves to hold together magnetically two members which are already in contact with each other while they are moved by a manually-exerted force.

BRIEF DESCRIPTION OF FIGURES These and other objects and features of the invention will be more readily understood from a consideration of the following detailed description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating one preferred embodiment of a system in accordance with the invention;

FIG. 2 is a sectional view of electrically-energizable coupling apparatus suitable for use in the system of FIG. 1, shown in its normal or deenergized condition;

FIG. 3 is a view similar to that of FIG. 2, but showing the coupling means in its energized state as it is being operated during engine starting; and

FIG. 4 is an end view, partly in section, taken along the lines 4-4 of FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now by way of example only to the particular embodiment of the invention illustrated in detail in the drawings, there is shown a system comprising an engine 10, which may for example be a conventional diesel engine; a fuel injection pump 12 for injecting fuel into the cylinders of engine 10, which pump may also be of conventional form; and governor apparatus 14 which may be arranged to provide speed limiting or variable speed control by control of the fuel injection pump 12, in known manner. A fuel control member 16 is arranged as a crank arm for a rotatable shaft 18 in the governor apparatus 14. Shaft 18 is so arranged within governor apparatus 14 that, in one of its rotational positions, it provides for and permits normal controlled running of the engine, while in another rotational position thereof it produces excess fuel injection into the engine in in amounts suitable to enhance engine starting. These two positions of shaft 18 correspond to, and are produced by, the corresponding normal or engine-running" position of member 16 shown in full line in the drawing and the corresponding excess fuel or start position of member 16 shown in broken line at 16A.

In summary, fuel control member 16 is to be in the position shown in full line during normal operation of the engine, but is to be rotated to the position shown at 16A when it is desired to start the engine. In this example, a spring 20 operates on fuel control member 16 to bias it towards its normal enginerunning position, and therefore'the lower end of fuel control member 16 must be'pulled to the left in the drawing, against the force of spring 20, in order to produce the excess fuel starting condition. It will be understood that the nature and position of the spring 20 and of all of the elements of the governor apparatus 14 may be conventional in form.

Engine is provided with an electric starter 24 responsive to voltage applied between its terminals 26 and 27 to operate the engine during starting. Voltage for operating the starter is provided from battery 28 by way of starter pushbutton switch 30, in this case shown as located on the operators side of a suitable dashboard or control panel 32 secured to the same frame 33 as engine 10 and its associated components.

Also mounted on dashboard 32 is a manually operable control arrangement 34 comprising a control knob 36, a plunger shaft 38 connected thereto, and a sleeve or bushing arrangement 40 mounted on dashboard 32 and within which shaft 38 may slide. A compression spring 42 is held within bushing 40, so as to be compressed by an end plate 44 secured to one end of piston 38, as knob 36 is pulled out by an operator; thus spring 42 urges control knob 36 and shaft 38 to the right, i.e. toward the normal inactivated position shown in full line in FIG. 1.

Attached to end plate 44 is a drive cable 46, and attached to the lower end of control member 16 is another drive cable 48; cables 46 and 48 may be of the type known as Bowden cables and may be secured to the corresponding parts by any appropriate arrangement of slots, bores, setscrews, etc. as may be convenient in the particular application. It will be appreciated that if cables 46 and 48 were joined directly together to form a single integral cable, then pulling out of control knob 36 by an operator would act directly to rotate fuel control member 16 from its normal engine-running position to its excess fuel position, and subsequent release of knob 36 would cause fuel control member 16 and knob 36 to return to their normal positions under the actions of springs 20 and 42. However, instead the inner adjacent ends of cables 46 and 48 are connected to opposite ends of a coupling means 50 in the form of a special electromagnetic clutch.

Coupling means 50 comprises a first force-transmissive member in the form of a reciprocable plunger 52 slideable therein and a second force-transmissive member in the form of a reciprocable plunger 54 also slideable in coupling means 50. Plunger 52 is connected at its outer end to cable 48 and plunger 54 is connected at its outer end to cable 46. Coupling means 50 is electrically-energizable by way of a pair of electrical supply leads 60 and 62. When no electric current is provided over the latter leads, then plunger 54 is decoupled from plunger 52 so that pulling out of control knob 36 moves plunger 54 outwardly but has no effect upon fuel control member 16. However, leads 60 and 62 are connected to electric starter terminals 26 and 27 so that energizing voltage is applied to leads 60 and 62 whenever the starter pushbutton switch 30 is actuated.

Accordingly, when pushbutton 30 is actuated, coupling means 50 operates to hold the two plungers 52 and 54 against each other, and pulling out of control knob 36 at this time then produces the desired movement of plunger 52 and resultant rotation of fuel control member 16 to the excess fuel position shown at 16A. However, as soon as starter pushbutton switch 30 is released, coupling means 50 is deenergized, plunger 52 is decoupled from plunger 54, and fuel control member 16 is returned to its normal engine-running position by the action of spring 20. Continued, or later, operation of control knob 36 can therefore have no effect in producing the excess fuel condition until the starter switch 30 is again operated. Thus the arrangement shown provides automatic termination of the excess fuel condition, and prevents inadvertent actuation of the fuel control member to the excess fuel position before or after starting. Furthermore, when control knob 36 is released, the spring 42 returns the control knob to FIGS. 2-4 show one preferred embodiment of coupling means 50 in further detail. In this example, coupling means 50 comprises a pair of end of bushings 71 and 72 having axial bores-for slideably receiving the smaller diameter portions of the plungers 52 and 54. Shoulders 74 and 76 on the inner sides of end bushings 71 and 72 serve to mount the inner cylinder tube 78, which has an inner diameter such as to receive slideably the larger diameter and portions or poles 84 and 86 I of plungers 52 and 54 respectively. An outer cylindrical casing 88 extends over, and holds together, the end bushings 71 and 72. Under the action of the springs 42 and 20 shown in FIG. 1, plunger 52 normally seats itself in its rightmost position with its large diameter plunger pole 84 seated against the inner side of end bushing 71, while plunger pole 86, which preferably has a flat face mating closely with the opposing flat face of plunger pole 84, is held in its rightmost position with its plunger pole face bearing against that of plunger pole face 84.

Between inner cylinder tube 78 and outer cylindrical casing 88 there is disposed a generally cylindrical bobbin 90, typically of plastic or fiber material, on which is wound the electri cal winding 92, the two ends of which winding are connected to the leads 60 and 62. The winding 92 may be of simple cylindrical form. The plungers, bushings, outer casing and inner cylinder tube may all be of steel, with the result that electrical current through the winding 92 produces magnetic lines of force extending through and between plunger poles 84 and 86 to bond them together magnetically. In the absence of current through winding 92, pulling of of cable 46 to the left will have no effect upon the position of plunger 52; however, when the starter pushbuton switch 30 is operated to apply a voltage to the electric starter 24, voltage is thereby also applied to winding leads 60 and 62 to bond plunger poles 84 and 86 to each other magnetically, whereby pulling of cable 46 to the left will pull plunger 52 to the left and thereby operate fuel control member 16 to the desired excess fuel condition. The latter condition of the elements within the coupling means 50 is represented in FIG. 3.

It will be appreciated that when the starter switch 30 is opened so as to discontinue current through the leads 60 and 62, the winding 92 no longer provides sufficient magnetic flux to bond together plunger poles 84 and 86, so that plunger 52 then returns immediately to its right-hand position under the biasing infuence of spring 20; similarly, when control knob 36 is released, plunger 54 will be returned to the position shown in FIG. 2 in response to the biasing action of spring 42.

It is particularly noted that the coupling means 50 does not rely upon conventional solenoid action to produce the desired travel of plunger 52. Instead, this travel is produced by operation of the manual control knob 36, the coupling means 50 merely serving to provide magnetic bonding of plunger 52 to plunger 54. Accordingly, the current required for energizing the winding 92 to produce the desired operation is much less, e.g. l0 to 1 less, than that which would be required to move a plunger by solenoid action over the required travel distance against the spring forces typically involved in usual applicaions.

As an example only, the outer casing 88 of coupling means 50 may be about 2% inches long, 1-% inches in diameter, and provided with an outer mounting strap 96 holding it in a mounting cradle 98 which in turn is appropriately secured to the same frame 33 as is dashboard 32. The maximum travel distance provided for plunger 54 within the casing 88 may be about 1-% inches maximum, but the actual plunger travel is referably limited to a somewhat lesser distance, such as l-% its normal in position and at the same time urges plunger 54 to the right and into contact with plunger 52 inside of the coupling means 50. The coupling means 50 is thereby placed in condition for operation during the next starting cycle.

inches, by limiting the outward travel of plunger shaft 38 to a distance of l% inches as determined by the dimensions of the spring 42 and the working cylinder length in manual control 34. Each of the plungers 52 and 54 may have a smaller diameter of about one-half inch and a larger diameter of about 0.6

inches. The bobbin may have a winding diameter of approximately $4 inch and a winding length of about 1.8 inch, on

which there may be provided about 565 turns of No. 29 plain enamaled copper magnet wire, .011 inch in diameter. Such a coupling means will draw only about 2 amperes from a 24 volt battery and will enable pulling forces of at least about 35 pounds to be exerted on the fuel control member 16 by pulling of the control knob 36.

It is noted that the coupling means also serves as a forcelimiting device characterized by a predetermined maximum force which it can transmit for any given value of current through its winding. If the force applied exceeds this value, the plunger poles will be forced to separate and the clutch thereby disengaged or disabled. Accordingly the clutch also acts as a safety release operative in the event that the mechanism to be operated through the coupling means should jam. The force at which release occurs is smaller, the smaller the current through the winding. For example, if the mechanism at 18 jams, the maximum force which can be transmitted through coupling means 50 is about 35 pounds when 24 volts are applied across leads 60 and 62. If a greater force is applied manually at 36, the magnetic lines of force between plungers 52 and 54 will be insufficient to hold them in contact. Plunger 54 will then move to its stop at the left and plunger 52 will be free to return to its normal position. The amount of force transmitted through coupling means 50 may be controlled by selecting the proper voltage to be applied across the leads 60 and 62.

While the invention has been described with particular reference to specific embodiments thereof in the interest of complete definiteness, it will be understood that it may be embodied in any of a variety of forms diverse from those specifically described, without departing from the invention as defined by the appended claims.

I claim:

1. In a diesel engine system comprising a diesel engine, a fuel injection pump for supplying fuel to the cylinders of said engine, an excess fuel control member operable to a first position to produce excess fuel delivery to said engine, an electric starter for said engine, an electric battery for supplying voltage to operate said starter, and a starter switch to control ap plication of said voltage to said starter:

a manual control for said excess fuel control member;

a linkage between said manual control and said excess fuel control member;

an electromagnetic clutch in said linkage;

means responsive to operation of said starter to energize said clutch and thereby permit operation of said excess fuel control member to said first position by operation of said manual control;

means biasing said excess fuel control member to said second position; and

said clutch being deenergized when said starter is not being operated therey to permit said excess fuel control member to assume said second position thereof despite operation of said manual control when said starter is not being operated; said clutch comprising;

an energizing winding connected to said starter switch to be energized when said switch is closed to operate said starter and to be deenergized when said switch is opened;

a first plunger connected to said excess fuel control member and reciprocable adjacent said winding between a first and a second position corresponding to said first and second positions of said excess fuel control member;

a second plunger connected to said manual control and reciprocable adjacent said winding between a first position in which it bears against said first plunger in the first position of said first plunger, and a second posimen;

said winding, when energized, being effective to produce a magnetic field causing said first plunger to follow said second plunger as said second plunger is moved from said first position to said second position thereof; and

said winding, when deenergized, freeing said first plunger from said second plunger to permit said first plunger to return to said first osition thereof. 2. Apparatus m accor ance with claim 1, comprising first spring means urging said first plunger toward said first position thereof 3. Apparatus in accordance with claim 2, comprising second spring means urging said second plunger toward said first position thereof. 

